Weird Oktava Condenser Mic + Phantom P/S

[rodabod]

I picked up this weird Oktava MKE-15 mic recently which came with a phantom power supply.

Anyway, I've got a couple of questions regarding the P/S. They are very (embarrassingly) simple.

There is no plug on the power supply. Guess what - I would like to put a plug on it. There is a two core cable coming from the unit. Despite not being insulated, I would imagine that the unit is supposed to be used with just +/- connections.

Now, I've tried to follow the wiring to see where each of the two wire go, but I can't define which should be + and which should be -.

Is there a simple way to tell? I can't tell the polarity of the P/S transformer secondary compared to the primary - just 4 brown wires!

My next question; how can I tell which socket is the input and which is the output? Both sockets are wired in parallel - this seems a little strange to me - it would mean that it doesn't matter which way round, despite the different labels on the housing.

Finally, I was thinking that it might be a nice idea to add an earth connection to ground the case. After looking in the box, I noticed that the case was wired to a diode on one of the circuit boards - I don't know why. Should I just leave the case floating then?

Cheers,

Roddy

[/img]

 

[kaur]

It is electret.
Not worst russian electret.

:roll:
If I remember correctly 15v usual phantom circuit.
I have schematic somwhere.
Probably very simple make for 48v.

 

[mcs]

[quote author="rodabod"]

[/quote]
Are those two on the right transistors? Or are they nuvistors? They look a lot like the Russian nuvistors I have at least...

Best regards,

Mikkel C. Simonsen

 

[Marik]

[quote author="mcs"][quote author="rodabod"]

[/quote]
Are those two on the right transistors? Or are they nuvistors? They look a lot like the Russian nuvistors I have at least...

Best regards,

Mikkel C. Simonsen[/quote]

My bet those are electrolytics.

 

[rodabod]

[quote author="Marik"][quote author="mcs"][quote author="rodabod"]

[/quote]
Are those two on the right transistors? Or are they nuvistors? They look a lot like the Russian nuvistors I have at least...

Best regards,

Mikkel C. Simonsen[/quote]

My bet those are electrolytics.[/quote]

And the prize goes to......... Marik.

Yes, they are electros - well spotted. I bet they sound fantastic :razz: not.

Anyway, any clues as to the polarity of the transformer? I could just guess, but I don't want to blow it up.

 

[kaur]

http://groupdiy.twin-x.com/displayimage.php?album=lastup&cat=0&pos=0
I hope this works.
VD2 is about 6volt zener.
R2 4k ohms may be for 48 volt phantom little low.
try double or tripple size resistor.
and use power supply for something else.
no +-,pure 220 AC volts.
output about 15 DC volts.
elytics are old and dying,replace them all.

manual says:
handheld microphone with low frequency cut 3-5db 50-150Hz.
noise typical electret
active thing is IC: K513ue1b
no idea what is this

never used this for recording.
about year ago:
had capsule from mke15 and broken b#ringer xm200@.
married them with clue and royer FET like circuitry/or was it sumphting like scott helmke uses/ and given to my friend who plays bass and sings backvocals in punkrocka like band.
(was 3 back vocals & lead)
friend of mine who was disappointed earlier stage expirences brings this thing in soundcheck and after some testing soundguy says: put that microphone for lead vocal.
:grin: :grin: :grin:

months back compared the thing in live situation with sm87 and spoken word:
cheap s....
comparable but not in same weight category.

 

[rodabod]

[quote author="kaur"]
R2 4k ohms may be for 48 volt phantom little low.
try double or tripple size resistor.
and use power supply for something else.

no +-,pure 220 AC volts.

output about 15 DC volts.
[/quote]

Thanks Kaur, you are a good guy.

So, is this a 15V supply?

I would like a 48V supply. Should I change R2 to make 48V?

Can I use my +/- 220V AC mains?

Thanks,

Roddy

 

[kaur]

Hmmmmm
I'm not a good guy. :twisted:
rrgh
Yes it is 15 volt supply,
and
its worth nothing.
use transformer like PRR posted:
http://www.groupdiy.com/index.php?topic=6469&highlight=purists+faint
its big enough for some IC's
and there are other posts for this
regulators &more

but for microphone find xlr connector/when yours not include that/
and make cable
DIN 2-goes to XLR ground 1
Din 1- goes to XLR hot 2
DIN 3-goes to XLR cold 3
beef up R2 in microphone little,say 10kohms and connect this thing in your usual mic pre with 48 volt phantom.